Electric lamp signaling apparatus



.2,1949 L. J. DAVIES ml. 2,471,966

-ELECTR'IC LAMP SIGNALING APPARATUS Filed Feb. 11, 1948 I nventors: I L.eonaT"dJ.Da.\/ies,

Their"- Attorney.

Har-r-y Kboubne,

Patented Aug. 2, 1949 ELECTRIC LAMP SIGNALING APPARATUS Leonard J. Davies and Harry K. Bourne, Rugby, England, assignors to General Electric Company, a corporation of New York Application February 11, 1948, Serial No. 7,634 In Great Britain -October 18, 1938 Section 1, Public Law 690, August ,8, 1946 Patent expires October 18, 1958 3 Claims. (01. 1-77-339i This invention relates to electric lamp signalling apparatus with units of the type described in British Patent Serial Number 579,034, the complete Specification of which was accepted July 22, 1946.

The lamps there described are particularly suitable for signalling purposes and consist of high candle power mercury vapour discharge lamps of small dimensions each enclosed within a movable shutter. The shutters are made of such small mass and dimensions that they may be operated electromagnetically to expose the light source so that high speed visual signalling can be performed. With this method of operation, while the shutter encloses the lamp, the watts supplied to the lamp need only be a fraction, for example a tenth or a quarter of the watts supplied when the shutter is open. The thermal lagging efiect of the shutter keeps the lamp at such a pressure and temperature that when extra energy is supplied to it, the brilliancy of the source immediately increases.

The lamp with the shutter mechanism may be hermetically sealed in an outer glass which may be provided with bi-post terminals or the lamp mechanism may be mounted within a glass cover.

Lamps of the above type are particularly suitable for mast-head signalling, but if the horizontal candle power required is large and is obtained from one lamp only, the size of the lamp is unduly increased and the shutter mechanism because of its increased mass becomes unwieldy and slow in movement.

The object of the present invention is to overcome this diflicultyand to that end it comprises a mast head signalling lamp including a number of lamps such as above described suitably supported around the mast, for example four or six mounted around the periphery of a circular member surrounding the mast, in such a manner that sufiicient horizontal candle power is provided in any direction. As each lamp requires its own choke and as the method of signalling is to shortcircuit a portion of the choke by means of a signalling key either direct or through a relay controlled by the key, all the lamps forming the signalling device may be controlled from one key which actuates as many relays as there are chokes, the relays being so connected that each one short-circuits the necessary part of its associated choke. It will be understood that if the current supply available is direct current, resistances will be used instead of chokes.

This invention further consists in so arranging the shutter mechanisms that they operate in L'li ' the type above described. The circuits of these lamps is shown in Fig. 3, where three lamps only are shown, but it will be understood that the circuit of each lamp is identical. The lamps 3 are connected to a source of alternating current through the leads 4 and have chokes 5 connected in series with them. These chokes are each divided into two portions, one of which is adapted to be short-circuited by a relay 6 connected in a suitable supply circuit l0 and controlled by a single tapping key switch 1, so that the chokes are short-circuited simultaneously.

Each lamp 3 has a series connected solenoid 8 which attracts a plunger linked to a Shutter 9 of any suitable type. When a portion of impedance 5 is short-circuited the current flowing through the lamp increases sufl'iciently to operate the plunger and the associated shutter mechanism.

Signalling apparatus as above described has the advantage that sufficient horizontal candle power can be secured in any direction and the moving parts of the shutters are kept small, so that reliable high speed operation can be secured. Also as the lamps are connected in parallel if one lamp fails, continuity of signalling can be secured While a replacement is being made. Even if more than one lamp fails or is destroyed, satisfactory signalling can still be effected.

While we have illustrated and described a particular embodiment of our invention, modifications thereof will occur to those skilled in the art. We desire it to be understood, therefore, that our invention is not to be limited to the particular arrangement disclosed, and we intend in the appended claims to cover all modifications which do not depart from the spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A signal system comprising a plurality of electric lamps, said lamps being provided with shutters, an impedance unit in series connection with each of said lamps, magnetic means for short circuiting a part of each of said impedance units, a tapping key switch means for operating said magnetic means to open said shutters simultaneously, and electric connections connecting said magnetic means in parallel with each other and in circuit with said tapping key switch.

2. A signal system comprising a, plurality of electric lamps arranged around a mast, said lamps being provided with magnetically operated shutters, an impedance unit connected in circuit with each of said lamps, said impedance units being divided each into two parts, a relay for short-circuiting one part of each of said units, and a tapping key switch connected to operate said relays so as to short-circuit simultaneously all of said one part of said units thereby to operate said shutters simultaneously.

3. A signal system comprising a plurality of electric lamps arranged around a mast, said lamps being provided with magnetically operated shutters, an impedance unit connected in circuit with each of said lamps said impedance units being divided each into two parts, a relay for short-circuiting one part of each of said units, magnetic means for operating each of said relays, a tapping key switch, and electric connections connecting said magnetic means in parallel with each other and in circuit with said tapping key switch.

LEONARD J. DAVIES.

HARRY K. BOURNE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'IENTS Number Name Date 283,073 Capron Aug. 14, 1883 315,035 Holtzer Apr. 7, 1885 

